What is the next state of initial in spanning-tree protocol？

Which of the following describes the roles of devices in a WAN?（）

what is the advantage of policing opposite to shaping？

當(dāng)將多個交換機加入到MST region當(dāng)中會發(fā)生什么（what happen）？

QoS Mechanisms：問在部署QoS中要用的3個mechanisms是什么？

The Frame Relay network in the diagram is not functioning properly.What is the cause of the problem?（） 

Refer to the exhibit.Which statement describes DLCI 17?（）

Which of the following are key characteristics of PPP?（）

DHCP SERVER在給一個網(wǎng)段設(shè)置POOL時，該網(wǎng)段路由器接口地址能不能放入POOL，能why，不能why。

SPT初始狀態(tài)之后的一個狀態(tài)是什么？